A 19-year-old man who admitted having sex with a girl of 12 and molesting her 11-year-old sister was sent to a rehabilitation centre yesterday. Yau Chi-ho, 19, pleaded guilty in the District Court on October 4 to unlawful sexual intercourse with a girl under the age of 13 and indecent assault. The offences were committed separately in the girls' grandmother's flat between March and April. In sentencing, Judge Peter Longley warned the defendant that he could expect a long jail term if he reoffended.